04 Gmc Sierra 3500 Duramax Diesel 4x4 on 2040-cars

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GM faces possible class action lawsuit over 8-speed transmission

General Motors has been hit with a class-action lawsuit from owners who allege the eight-speed automatic transmission found in several rear-wheel-drive Chevrolet, Cadillac and GMC models between the 2015 and 2019 model years has a defect that causes the vehicles to hesitate and jerk when accelerating or slowing down. The lawsuit was posted to ClassAction.org and spotted by GM Authority. Problems with GM's Hydra-Matic 8L90 and 8L45 transmissions have been well-documented on Internet forums and via complaints filed with the National Highway Traffic Safety Administration, with many reporting damage to their vehicles. The lawsuit was first filed in December in U.S. District Court for the Southern District of Florida but appears to have been transferred recently to New York. Autoblog sought comment from Theodore Leopold, the lead attorney for the plaintiffs. "These transmissions have a common defect," the complaint reads. "Drivers attempting to accelerate or decelerate their cars feel a hesitation, followed by a significant shake, shudder, jerk, clunk, or 'hard shift' when the vehicle's automatic transmission changes gears." The problem also occurs when the vehicles accelerate in a single gear, without shifting, the plaintiffs allege. "Drivers have reported that the shift is sometimes so violent, they feel as though they have been hit by another vehicle." The problem is believed to center on the transmission, torque converter or both. The complaint says it causes undue friction, causing hydraulic systems and gears to function improperly and sometimes leaves metal shavings throughout the transmission, leading to costly repairs and replacement of parts or the entire transmission. It says GM has known about the problems since shortly after it introduced the transmissions, and has issued 13 technical service bulletins, none of which have resolved the problem. GM declined to comment on the lawsuit. The plaintiffs say GM should have warned consumers about the issues and covered repairs under each vehicle's three-year/36,000-mile bumper-to-bumper warranty. They're seeking statewide classes in at least six states: California, Florida, Illinois, New York, Oklahoma and Texas.

GMC Sierra Denali CarbonPro bed is finally, almost here

GMC revealed the Sierra 1500 with the optional CarbonPro bed on March 1, 2018. The bed wasn't available at launch, though. You can't buy it now, either, but it will hit dealerships with limited availability after production starts in early June, exclusively for the Denali 1500 and AT4 1500 trims. The carbon floor and sides replace the steel panels in a normal bed, providing "strength, durability, and scratch resistance" and a potential 59-pound weight saving, depending on the truck's configuration. To make sure the bed had a chance, development engineers replicated "extreme use scenarios" like dropping 1,800-pound gravel loads, 450-pound steel drums, and cinder blocks from various heights. They put a 250-pound man on a snowmobile with studded tracks, had him drive into the bed and then go wide-open throttle. We're told the result was "minimal scratching." On top of the extreme weather testing any vehicle goes through, the team also put a generator in the bed and aim the exhaust into a corner to ensure vibration and direct heat wouldn't deform the carbon fiber. Because of the finer shaping area-specific strength possible with carbon fiber, the bed provides one cubic foot of additional payload space by having its sidewalls pushed further out. The CarbonPro bed doesn't need a bedliner, and is grained at the top for better traction but smooth on the bottom for easier hosing down and dirt removal. Tie-downs at the front of the bed work with molded indentations to hold motorcycle tires, and slots in the sidewalls hold two-by-sixes. The truck maker says the carbon-lined payload area confers "best-in-class dent, scratch and corrosion resistance," but we suppose the nation's pickup truck army will prove that or not. The trucks likely won't have the hardest life at the start, since the Sierra Denali costs $56,790 before even a basic option like four-wheel drive. The real test probably won't come until around 2029, when third owners begin treating their aerospace-inspired thoroughbreds like dray horses.

2019 GMC Sierra Denali MultiPro tailgate and CarbonPro bed explained

When the 2019 Chevy Silverado debuted at the Detroit Auto Show in January, GM's Mark Reuss promised that the new 2019 GMC Sierra would have some significantly different styling and features than its corporate sibling. Previously, the Sierra has been little more than a Silverado with new front and rear fascias and some extra chrome inside and out. Well, Reuss was right. In addition to new sheetmetal, the Sierra exclusively gets the slick MultiPro tailgate and CarbonPro carbon-fiber bed box The tailgate really is trick. At the debut, GMC had multiple demonstrations, with engineers walking us through all six different configurations. Like all Sierra tailgates, the MultiPro version uses an aluminum skin to reduce weight. It's easy to tell which tailgate is which, as the MultiPro has a distinct cutout in the middle where it can fold down or extend. It can be used to extend the bed, drop to allow easier access, provide a sort of workbench, or be used as a step to help get into the bed. Yes, there's even a handle. Ford who? The step itself can support up to 375 pounds, 75 pounds more than Ford's similar tailgate step. This tailgate really is unique to the Sierra and is standard on SLT and Denali models. That said, the power-operated tailgate from the Silverado won't be coming to the GMC. Chevy gets its own exclusive, too. The Sierra's other big exclusive is the carbon-fiber reinforced plastic bed box. CFRP replaces steel inside the bed though not on the fenders. The bed uses four pieces; one for the bottom, one in the back and two along the sides. This isn't a CFRP. There is no steel hiding underneath these panels. Just take a peek underneath. The bed is a composite that uses 1-inch carbon-fiber threads, not a weave. Sheets of CFRP are molded and quenched — a process where the plastic coagulates and solidifies, locking in the carbon fiber — in just 60 seconds. That allows GMC's supplier to crank out these much more quickly. The finish looks like black fiberglass, though an engineer said that this wasn't the final production version. The final model will have different textures in order to improve grip and keep things from sliding around. GMC is touting the material's dent and corrosion resistance, though it remains to be seen how well it holds up to cracking. A video at the reveal showed people going after it with hammers and cinder blocks, but in-person demonstrations weren't available.